allen



E.G.ALLEN. STEA M SAFETY VALVE.

No. 81,820. I Pat'ented Aug. 25, 1868.

E. G- ALLEN, OF BOSTON, MASSACHUSETTS.

Letters Patent No. 81,320, dated August 25, 1868.

IMPROVEMENT IN STEAM SAFETY-VALVES.

. an swan were in in that jitter hated mm muting 112M at its $211M.

I Be it known that I, E. G. ALLEN, of Boston, in the county of Suffolk, and State of Massachusetts, have invented a new and improved Lock-Up and Alarm Safety-Valve, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making a part of this specification, in which a Figure 1 represents an elevation of a safety-valve embodying my invention.

Figure 2 is a vertical section of the same. i

Figure 3 is .a top view, with the cover of the valve-casing removed; and

Figure 4 is'a section of a valve and a casing on an enlarged scale.

The object of my invention is to produce a valve which shall insure certainty of relief to the boiler under any required pressure, and which willsound an alarm at the first escape of'steam, by means of a whistle, and, a so, which shall be so protected as to prevent it from being tampered with under any circumstances without detection.

And the invention consists in the combination, with a tapering volute spring, of a sleeve,'upon which the said spring is supported, and which rests directly upon the valve, enclosing the valve-stem, thus causing the spring to press evenly upon the valve, and insuring an unfailing and precise action of the same. i

The invention further consists in providing the escape or let-oif pipe, near the whistle, with a series of openings or. holes, whose combined area is equivalent to that of the valve-opening,- thcreby securing a free discharge of the steam, and preventing any tampering with the valve through the said pipe.

The invention further consists in so arranging a whistle with reference to the safety-valve that, at the first escape of steam from said valve, the whistle will be sounded, and will continue to sound so long as the steam continues to escape. N v

Referring to the drawings, A represents the valve-box, in which is fitted, in the usual manner, the valve a. To the upper side of the valve a is attached the spindle c, which is enclosed by a sleeve, el, supported.upon the valve at its lower end. The sleeve cl passes through the nut e, which is screwed to the upper plate r of the case A. The sleeve is fitted-snugly, but so as to slide freely in the said nut. On the upper end of the sleeve d is supported the tapcringvolute spring g, the upper portion orlarger diameter of which is let into a ring or bearing, It, provided with openings on either side, which it over rods is attached to the plate 1', and are threaded at their upper ends, by which means the spring may be readily adjusted, by nuts I Z, to any required pressure.

To the plate r is attached the casing D, which encloses the spring-g, and is provided with a cover, m, which is attached to thecasing, by'incans of what are termed bayonet-joints, consisting of a right-angled slot, fitting over a pin on each side of the'inner surface of the casing, so that by placing the cover on the casing, and turning it uponthejoints until a hasp on the outside is brought upon the eye, which holds a padlock, the same can be sccured,locked, or sealed, and all access to the valve or spring is eil'ectually prevented by any unauthorized person.

The upper portion of the escape-pipe O is provided with a series of holes, the combined areas of which are equal to the area of the valve-opening, so as to allow of a free discharge of the steam, and, at the same time, prevent any access to the valve through such pipe..

The-form 'of valve I design using is shown in fig. 4. It is constructed with an enlargement above the seat, in the under side of which is a groove, or it may be a V-shaped recess, or simply a flange, so as to provide a large surface for the action of the steam at the moment the valve rises from its seat, for the purpose of counterbalancing the pressure of the spring, and admitting of an enlarged opening to the valve. The valve being steadily retained inposition by means of the spindle and sleeve, a free and precise action will be always insured.

The valve can be adjusted to any desired pressure, and when so adjusted, and the cover secured by a lock or seal, cannot be altered or tampered with in any way without violence to the case so as to lead to discovery.

What I claim as new, and desire to secure by Letters Patent, is-

1. The combinationof a-spring, g, sleeve 2?, and stem 0, substantially as and for the purpose specified- 2. Constructing the let-elf pipe with the perforations s s s, as and for the purpose described.

3. Se arranging a whistle with reference to the safety-valve that, at the first escape of the steam from said valve, the whistle will be sounded, and will continue to sound so long as the steam continues to escape, substantially as shown and described.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

' E. G. ALLEN.

Witnesses:

D. N. PIOKERING, J. H. ADAMS. 

